6.6-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman gregkh@linuxfoundation.org
This reverts commit b522229a56941adac1ea1da6593b2b5c734b5359 which is commit 91ccc6e7233bb10a9c176aa4cc70d6f432a441a5 upstream.
The workqueue patches backported to 6.6.y caused some reported regressions, so revert them for now.
Reported-by: Thorsten Leemhuis regressions@leemhuis.info Cc: Tejun Heo tj@kernel.org Cc: Marek Szyprowski m.szyprowski@samsung.com Cc: Nathan Chancellor nathan@kernel.org Cc: Sasha Levin sashal@kernel.org Cc: Audra Mitchell audra@redhat.com Link: https://lore.kernel.org/all/ce4c2f67-c298-48a0-87a3-f933d646c73b@leemhuis.in... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/workqueue.c | 142 ++--------------------------------------------------- 1 file changed, 7 insertions(+), 135 deletions(-)
--- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -281,16 +281,6 @@ struct wq_flusher { struct wq_device;
/* - * Unlike in a per-cpu workqueue where max_active limits its concurrency level - * on each CPU, in an unbound workqueue, max_active applies to the whole system. - * As sharing a single nr_active across multiple sockets can be very expensive, - * the counting and enforcement is per NUMA node. - */ -struct wq_node_nr_active { - atomic_t nr; /* per-node nr_active count */ -}; - -/* * The externally visible workqueue. It relays the issued work items to * the appropriate worker_pool through its pool_workqueues. */ @@ -336,7 +326,6 @@ struct workqueue_struct { /* hot fields used during command issue, aligned to cacheline */ unsigned int flags ____cacheline_aligned; /* WQ: WQ_* flags */ struct pool_workqueue __percpu __rcu **cpu_pwq; /* I: per-cpu pwqs */ - struct wq_node_nr_active *node_nr_active[]; /* I: per-node nr_active */ };
static struct kmem_cache *pwq_cache; @@ -1427,31 +1416,6 @@ work_func_t wq_worker_last_func(struct t }
/** - * wq_node_nr_active - Determine wq_node_nr_active to use - * @wq: workqueue of interest - * @node: NUMA node, can be %NUMA_NO_NODE - * - * Determine wq_node_nr_active to use for @wq on @node. Returns: - * - * - %NULL for per-cpu workqueues as they don't need to use shared nr_active. - * - * - node_nr_active[nr_node_ids] if @node is %NUMA_NO_NODE. - * - * - Otherwise, node_nr_active[@node]. - */ -static struct wq_node_nr_active *wq_node_nr_active(struct workqueue_struct *wq, - int node) -{ - if (!(wq->flags & WQ_UNBOUND)) - return NULL; - - if (node == NUMA_NO_NODE) - node = nr_node_ids; - - return wq->node_nr_active[node]; -} - -/** * get_pwq - get an extra reference on the specified pool_workqueue * @pwq: pool_workqueue to get * @@ -1532,17 +1496,12 @@ static bool pwq_activate_work(struct poo struct work_struct *work) { struct worker_pool *pool = pwq->pool; - struct wq_node_nr_active *nna;
lockdep_assert_held(&pool->lock);
if (!(*work_data_bits(work) & WORK_STRUCT_INACTIVE)) return false;
- nna = wq_node_nr_active(pwq->wq, pool->node); - if (nna) - atomic_inc(&nna->nr); - pwq->nr_active++; __pwq_activate_work(pwq, work); return true; @@ -1559,18 +1518,14 @@ static bool pwq_tryinc_nr_active(struct { struct workqueue_struct *wq = pwq->wq; struct worker_pool *pool = pwq->pool; - struct wq_node_nr_active *nna = wq_node_nr_active(wq, pool->node); bool obtained;
lockdep_assert_held(&pool->lock);
obtained = pwq->nr_active < READ_ONCE(wq->max_active);
- if (obtained) { + if (obtained) pwq->nr_active++; - if (nna) - atomic_inc(&nna->nr); - } return obtained; }
@@ -1607,26 +1562,10 @@ static bool pwq_activate_first_inactive( static void pwq_dec_nr_active(struct pool_workqueue *pwq) { struct worker_pool *pool = pwq->pool; - struct wq_node_nr_active *nna = wq_node_nr_active(pwq->wq, pool->node);
lockdep_assert_held(&pool->lock);
- /* - * @pwq->nr_active should be decremented for both percpu and unbound - * workqueues. - */ pwq->nr_active--; - - /* - * For a percpu workqueue, it's simple. Just need to kick the first - * inactive work item on @pwq itself. - */ - if (!nna) { - pwq_activate_first_inactive(pwq); - return; - } - - atomic_dec(&nna->nr); pwq_activate_first_inactive(pwq); }
@@ -4081,63 +4020,11 @@ static void wq_free_lockdep(struct workq } #endif
-static void free_node_nr_active(struct wq_node_nr_active **nna_ar) -{ - int node; - - for_each_node(node) { - kfree(nna_ar[node]); - nna_ar[node] = NULL; - } - - kfree(nna_ar[nr_node_ids]); - nna_ar[nr_node_ids] = NULL; -} - -static void init_node_nr_active(struct wq_node_nr_active *nna) -{ - atomic_set(&nna->nr, 0); -} - -/* - * Each node's nr_active counter will be accessed mostly from its own node and - * should be allocated in the node. - */ -static int alloc_node_nr_active(struct wq_node_nr_active **nna_ar) -{ - struct wq_node_nr_active *nna; - int node; - - for_each_node(node) { - nna = kzalloc_node(sizeof(*nna), GFP_KERNEL, node); - if (!nna) - goto err_free; - init_node_nr_active(nna); - nna_ar[node] = nna; - } - - /* [nr_node_ids] is used as the fallback */ - nna = kzalloc_node(sizeof(*nna), GFP_KERNEL, NUMA_NO_NODE); - if (!nna) - goto err_free; - init_node_nr_active(nna); - nna_ar[nr_node_ids] = nna; - - return 0; - -err_free: - free_node_nr_active(nna_ar); - return -ENOMEM; -} - static void rcu_free_wq(struct rcu_head *rcu) { struct workqueue_struct *wq = container_of(rcu, struct workqueue_struct, rcu);
- if (wq->flags & WQ_UNBOUND) - free_node_nr_active(wq->node_nr_active); - wq_free_lockdep(wq); free_percpu(wq->cpu_pwq); free_workqueue_attrs(wq->unbound_attrs); @@ -4889,8 +4776,7 @@ struct workqueue_struct *alloc_workqueue { va_list args; struct workqueue_struct *wq; - size_t wq_size; - int name_len; + int len;
/* * Unbound && max_active == 1 used to imply ordered, which is no longer @@ -4906,12 +4792,7 @@ struct workqueue_struct *alloc_workqueue flags |= WQ_UNBOUND;
/* allocate wq and format name */ - if (flags & WQ_UNBOUND) - wq_size = struct_size(wq, node_nr_active, nr_node_ids + 1); - else - wq_size = sizeof(*wq); - - wq = kzalloc(wq_size, GFP_KERNEL); + wq = kzalloc(sizeof(*wq), GFP_KERNEL); if (!wq) return NULL;
@@ -4922,12 +4803,11 @@ struct workqueue_struct *alloc_workqueue }
va_start(args, max_active); - name_len = vsnprintf(wq->name, sizeof(wq->name), fmt, args); + len = vsnprintf(wq->name, sizeof(wq->name), fmt, args); va_end(args);
- if (name_len >= WQ_NAME_LEN) - pr_warn_once("workqueue: name exceeds WQ_NAME_LEN. Truncating to: %s\n", - wq->name); + if (len >= WQ_NAME_LEN) + pr_warn_once("workqueue: name exceeds WQ_NAME_LEN. Truncating to: %s\n", wq->name);
max_active = max_active ?: WQ_DFL_ACTIVE; max_active = wq_clamp_max_active(max_active, flags, wq->name); @@ -4946,13 +4826,8 @@ struct workqueue_struct *alloc_workqueue wq_init_lockdep(wq); INIT_LIST_HEAD(&wq->list);
- if (flags & WQ_UNBOUND) { - if (alloc_node_nr_active(wq->node_nr_active) < 0) - goto err_unreg_lockdep; - } - if (alloc_and_link_pwqs(wq) < 0) - goto err_free_node_nr_active; + goto err_unreg_lockdep;
if (wq_online && init_rescuer(wq) < 0) goto err_destroy; @@ -4977,9 +4852,6 @@ struct workqueue_struct *alloc_workqueue
return wq;
-err_free_node_nr_active: - if (wq->flags & WQ_UNBOUND) - free_node_nr_active(wq->node_nr_active); err_unreg_lockdep: wq_unregister_lockdep(wq); wq_free_lockdep(wq);